Adjustable chair



Ju y 1944- R. c. ANGELL 678 ADJUSTABLE CHAIR Filed Oct. 5, 1941 14 Sheets-Sheet 1 FIG 1.

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(Ittomeg Jul 4, 1944. Q ANGELL 2,352,678

ADJUSTABLE CHAIR Filed Oct. 3, 1941 14 Sheets-Sheet 3 Zhwentor R. C. ANGELL ADJUSTABLE CHAIR Filed Oct. 5, 1941 14 Sheets-Sheet 4 M w 1 H July 4, 1944.

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ADJUS TABLE CHAIR Filed Oct. 3, 1941 14 Sheets-Sheet 7 \mWNw m Z mmmw @QN attorney 1 I 0 J a m Snventor 75013617 (f/Mg/Z,

July 4, 1944. Q ANGELL 2,352,678

ADJUSTABLE CHAIR Filed Oct. 3, 1941 14 Sheets-Sheet 9 attorney July 4, 1944. R. c. ANGELL ADJUSTABLE CHAIR Filed 001'. 3, 1941 14 Sheets-Sheet l0 Inventor 4'2 39/561? fliZj/PZ/l.

Gttorneg July 4, 1944. R. c. ANGELL ADJUSTABLE CHAIR Filed 001:. 3, 1941 14 Sheets-Sheet '11 I 3nventor 25M attorney y 1944? c. ANGELL, 2,352,678

ADJUSTABLE CHAIR Filed Oct. 5, 1941 14 sheets-sheet 12' 3nventdr July 4, 1944. R c, ANGELL 2,352,678

' ADJUSTABLE CHAIR Filed Oct. 3, 1941 14 Sheets-Sheet 13 FIG. 24'. J33

3nnentor (Ittorneg July 4, 1944.

R. C. ANGELL ADJUSTABLE CHAIR Filed Oct. 5, 1941 14 Sheets-Sheet l4 FIG'iZB.

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III... lllllllw $5 Patented July 4, 1944 UNiTEo STATE-s PATENT ori ce Y anwsmnrn chant RobertGAngell, Prince Bay, N. in, .assignor to The S. swam-ment l Manufacturing Company, a corporation of Pennsylvania AppIicatIonOctober-S, 1941, Serial no. 413,448 f 1116 m, -;(Cl.155.- -25) My invention relates particularly tothat. class".

of adjustable chairs that are,"commonlyyemployed" by dentists, physicians, barber's; orotherpra,cti

'. -''.';sp'ecifically described comprises;---an.- adjustable chair having a base upon which'a'chair frame consequently requiring him to balance his body on'one foot during actuation oflthe foot con- 'trollingmechanism. My invention also comprehends a non-vibra torymounting for the power' producing unitincluding the associated motor and pump, comprising a yokelike frame embracing said unit and having relatively spaced independent resillent supports by which said unit is cradled.

"'I'he.;.'f0rm' ofmy invention *as'herein more supporting carriage is mounted to 'rotate, being supported by rollers arranged to traverse a circular track on said base, and providing, 8; reservoir-for.fluid, a pedestal frame section carrying an extensible and retractible seat supporting may be efiicientlyjefiectediby theemployment. of

a single chain or other-flexible-connecting;ele-.

.a relatively telescoping shaft upon which the seat frame is mounted, said pedstal having connected tensible seat supporting pedestal-n enib rs.;are v t I bodystructure which connects said cylinder with guided solely by rollers so'relatively disp sedjasto maintain said pedestal members axially-aimed while moving up and; downwlthout the aidot friction producing relativelyslidingielements.

. Further objects of my inventionare to, provide an adjustable chair-inwhichthe relativelyexstructure including a pedestal sleeve section and therewith. a cylinder cooperative with a stationarypiston whose hollow tubular piston 'rod projects upwardly from a piston supporting valve a fluid compressing unit including a pump-and motor resiliently mounted on said chair frame I supporting carriage, and an automatically and My invention comprehends, such 1 antarran'ee ment of balanced associated. elements "thatlithe seat supporting shaft is disposed to the-rear with respect to the axis of the chair proper while its lifting elements including the piston and its cooperative cylinder are disposed'forward of said chair axis. 1 t v r I My invention comprises a readily removable and replaceable closure for the-operative mechanism that efi'ects the raising and lowering of the chair seat, and includes relatively stationary and movable telescopic sections that afford an envelope that is extensible and retractible in accordance with the movement of the extensiblev and retractible seat supporting elements.

My invention includes such an arrangement of the cooperative controlling mechanism as to effect actuation of the fluid releasing valve :by lift- 1 lug it from its seat from beneath; and also inc'uies such an arrangement of valve actuating structure as to provide relatively linked foot controlling pedals disposed in convenient positions at relatively opposite sides of the chair base, and 50 mounted to move about vertical axes that they may be actuated to effect raising and lowering of the chair seat by a lateral movement of the foot of the operator without necessitating said operator raising his foot from the floor and manually controlled relief valve for relieving the fluid pressure in said cylinder to efl'ect lowering of the chair seat from an elevated position.

My invention also includes all of the various novel features of construction and arrangement as hereinafter more definitely specified.

In the accompanying drawings, Figure 1 is a perspective view of the adjustable chair constructed in accordance with my invention, and extended to its rdaximum raised position; Fig. 2 is a perspective view of said chair shownin its lowered or normal position; Fig. 3 is a plan' view of said chair-with theseat and its cooperative parts, including its supporting cross-head structure removed for convenience of illustration; Fig. 4 is a central diagonal transverse vertical sectional view of said chair exclusive of the seat and its cooperative parts, taken on the line 44 in Fig. 3, the seat cross-head being rotated into-a front view position for convenience of illustration; T

Fig. 5 is a central vertical longitudinal sectional view taken on the line 5-5, in Fig. 3, substantially coincident with the axial plane of said chair,

, but being staggered to bring certain parts of the chair structure into the plane of section; Fig. 6 is a central vertical longitudinal sectional view similar to Fig. 5 but showing the structural parts of said chair retracted to minimum height, corresponding to the position of the chair as shown in Fig. 2, and omitting the motor for convenience of illustration; Fig. 7 is a fragmentary vertical sectional view taken on the line '1-1 in Figs. 3 and 23; Fig. 8 is a fragmentary vertical sectional view taken on the line 8-5 in Fig. 3; Fig. 9 is a. side elevational view of the frame pedestal section showing a front face of the controlling lever mechanism including the mercury switch which controls the electric motor and its cooperative pump; Fig. 10 is a fragmentary elevational view rshown partly in section for convenience of illustration, and showing a side view of the structure illustrated in Fig. 9 as viewed from the right hand side of said figure; Fig. 11 is a plan sectional view of the chair frame supporting carriage taken on the line 11-1! in Fig. 9; Fig. 12 is a plan sectional view of the foot-pedal switch lever unit illustrated in Fig. 9 taken on the line 12 in said Fig. 9,, and showing the parts in their normally inoperative position; Fig. 13 is a plan sectlonal view similar to Fig. 12, but taken at a lower level on the line 13-43 in Fig. 9; Fig. 14 is a plan sectional view similar to Fig. 12 but showing the.

lever shifted to the position wherein the motor is actuated to effect extension of the chair seat raising mechanism; Fig. 15 is a plan sectional view similar to Fig. 12, but showing the levers shifted to the position wherein the chair raising medium is released to permit the chair seat supporting mechanism to descend; Fig. 16 is a plan sectional view similar to Fig. 12, but showing. the relation of the levers in event the foot control lever be inadvertently held in position to raise the chair when it has reached the maximum upward movement, and the automaticstop releases the chair raising medium; Fig. 17 is a perspective view of the replaceable yielding foot-pedestal shields shown in plan view in Fig. 3 and in side elevation in Fig. 4; Fig. 18 is a rear elevational view of said shields; Fig. 19 is a front elevational view of the mercury switch supporting frame shown attached to a fragment of the chair frame supporting carriage and illustrating the switch in its operative position; Fig. 20 is a front elevational view of the motor panel, which is shown in plan view in Fig. 3, and upon which the resistor and capacitor are mounted; Fig. 21 is a front elevational view of the motor supporting frame with the motor fioatingly mounted therein; Fig. 22 is a side elevational view of the motor supporting frame per se, shown in Fig. 21, as viewed from the right side of said Fig. 21; Fig. 23 is a plan sectional view illustrating. the chair frame supporting carriage and showing the means for attaching the lowermost casing section thereto; Fig. 24 is a plan view of the assembled casing per se which envelope the seat raising mechanism; Fig. 25 is a fragmentary sectional elevatlonal view of the uppermost telescopic casing section illustrating the snap-on moulding guide attached thereto, the uppermost portion of which being broken away for convenience of il lustration; Fig. 26 is a similar fragmentary sectional elevational view of the uppermost intermediate telescopic casing section illustrating the snap-on moulding guide attached thereto; Fig. 2'1 is a perspective view of the snap-on moulding which serves as a guide for the cooperative telescopic casing sections to which it is attached as illustrated in Figs. 25, 26 and 29; Fig. 28 is a fragmentary plan sectional view of the telescopic casing section shown in Fig. 25, taken on the line 28-28 in said figure; Fig. 29 is a fragmentary plan sectional view of the telescopic casing section shown in Fig. 25, taken on the line 29-29 in'said figure; and Fig. 30 is a perspective view of the headed rivet which serves as an attachment for the snap-on moulding guides, best illustrated in Figs. 25, 26, 2'1 and 29, but also shown in Fig. 1.

In said figures, the chair base I comprises an annulus resting upon the floor and having the inturned flange 2 affording the circular horizontal track 3 provided by its upper surface and a sliding guide 5 provided by its under surface.

Mounted to rotate on said base I and depending through the opening therein is the chair frame supporting carriage 5 having its upturned wall 8 forming a fluid reservoir I having its floor 8 depending into as close proximity to the room floor upon which the base I stands as practical, and provided with a restricted preferably circular depression aifording a sump 9.

The chair frame supporting carriage 5 has the peripheral horizontally disposed flange 10; the outer peripheral edge ll thereof extends into close proximity to the inner edge 12 of the intumed flange 2 of the base I and so registers therewith that the upper surfaces of said flanges 2 and i0 preferably extend in a coincident horizontal plane.

Said chair frame supporting carriage 5 is mounted to rotate about its vertical axis, being provided with the ball-bearing rollers l5, l5 and I1 relatively disposed on axes separated by one hundred and twenty degrees, and arranged to traverse said circular track 3. Said rollers are preferably mounted on stud shafts 19, 25 and 21 respectively which are engaged in suitably provided bores 22, 23 and 25 in the respective bearing blocks 25, 25 and 21 respectively extending upwardly from the flange l0, and preferably formed in unitary relation therewith.

The chair frame supporting carriage 5 conveniently supports the frame pedestal section 29,

th lower laterally extended flange 30 of which rests upon the upper surface of the upwardly extending side walls 5 of said carriage 5 and is secured thereto by the tap bolts 31. Said frame pedestal section 29 includes an upper laterally extended flange 32 and an intermediate laterally extended flange 53.

The frame pedestal section 29 has its side wall 35 extended upwardly abov the flange 32 to a uniform height for the major portion of its circumferential extent, the remaining portion declining to the level of said flange 32, as shown in Figs. 5 and 9. Said frame pedestal section 29 is provided with four narrow vertically disposed openings 35, 31, 38 and 39, respectively extending between the flanges 32 and 33, and each being flanked by the ribs 42 and 53 joining said flanges, as illustrated in Figs. 9 and 11, and is also provided with the openings 55, 41, 48 and 59 alined with the openings 35, 31, 38 and 39, and similarly flanked by the ribs 50 and 51 extending upwardly from said flange 32.

Disposed in the several openings 35, 31, 38 and 39 are the rollers 52, 53, 55 and 55 respectively mounted to rotate on shafts 55, 51, 58 and 59 which are engaged in the respective ribs flanking the said several openings 35, 31, 38 and 39. and said rollers are so disposed as to project inwsiridlfy beyonddthte inner surface of the walls of sa rame pe es al section, as ma b Figs; 4, 5 and 11. y e seen in Similarly, rollers 50, 5|, 52 and 53 are disposed in the several openings 45, 41, 58 and 49, and mounted to respectively rotate on shafts 55, 55, 51 and 58 which are engaged in the respective ribs flanking the said several openings 45, 41, 48 and 49, and said rollers, like the rollers 52, 53, 54 and 55, are so disposed as to project inwardly to the same extent as said rollers 52, 53, 54 and 55, so as to cooperate therewith in guiding and maintaining the relatively movable telescoping pedestal sections in vertical position while traveling up and down with respect to sa d frame pedestal section, as will be more particularly described hereinafter.

The pedestal sleeve section 69 of the composite pedestal structure is mounted to move up and down within the frame pedestal section 29 and is provided with oppositely directed angular track strips I and II which are preferably cast integral with the body of the sleeve section 69, and provide a relatively hard and wear resisting sheath for the diagonally opposite exterior corner regions of said sleeve section 69 and serve as tracks for the rollers 52, 53, 54, 55, 90, BI, 62 and 63, as best shown in Fig. 3.

The pedestal sleeve section 99, like the frame pedestal section 29, has its walls provided with apertures I2, I3, I4 and I for the rollers 19, I1, I9 and I9 respectively mounted to rotate on the stud shafts 99, II, 92 and 93 engaged in the parallel ribs 95 and 99 which flank said apertures I2, I3, I4 and I5 and which also carry the stud shafts 99, 90, 9| and 92 on which rollers 93, 94, 95 and 95 extending through the apertures 91, 99, 99 and I00 in the walls of said sleeve section 99 rotate.

As shown in Figs. 3, 4, 5 and 11, the rollers 15, 11, I9, I9, 93, 94, 95 and 99 project inwardly slightly beyond the inner surface of the sleeve section to engage the seat support'ng shaft IN and to maintain it in a true vertical position and to thus guide it in its up and down movement.

Said seat supporting shaft IOI is preferably square in its cross-section and term'nates atits upper erd in a cylindrical boss I02 which provides a shoulder I03 upon which seat supporting cross-head I05 is mounted, said seat supporting cross-head having the trunnions I09 and I01,

upon which the chair seat, not shown, may rock,

and being of well known construct on, is illustrated in front elevation in Fig. 4 and in side elevation in Fig. 5. In Fig. 4, however, said cross-head I05 s, for convenience of illustration, rotated on its supporting shaft I0 I, out of its normal position and consequently appears to be slightly of! center, as illustrated in Fig. 4.

The chair seat supporting shaft IOI', as best illustrated in Fig. 5, is provided with the bore provid'ng the recess I09 in its lower erd arranged .to receive the buffer spring IIO which bears against the plunger buffer I I I having the periph eral flange II2 normally resting, when said shaft IN, is raised, upon the retaining plate I I3. In the lowermost position of the seat supporting shaft III, the plunger buil'er III rests in the recess II5 formed bya depression 11 the floor 9 of the fluid reservoir 1, in which position the spring III is compressed and tends to so support the weight of the seat supporting shaft III as to assist in starting said shaft IM and the parts carried thereby in its raisng movement. 7

As illustrated in Figs. 3, 4 and 5, the seat supporting shaft III is so connected with the pedestai sleeve section 99 that when said sleeve section is moved up or down, said seat supporting shaft III will move relatively up or down therein at double the speed of travel of sa'd sleeve section 99.

As best shown in Fig. 4, the seat supporting shaft III is connected by the coupling H0 w'ththe sprocket chain I II which extends around-the sheaves or sprockets I'I9 and I respectively dis- 7;;

posed at one side of the upper and lower ends of the pedestal sleeve section 99 and having their shafts I2I and I22 mounted in suitably provided bearing lugs I25 and I29 projecting outwardly from the side wall I21 of said sleeve section 69 and registering with openings I29 and I30 respectively extending. through said side wall I21 at the top and bottom of said sleeve section 99, and through which said sheaves or sprockets H9 and I20 are arranged to rotate.

The sprocket chain III is also connected at its opposite ends with the couplings I32 and I33 which are engaged with the side wall I35 of the frame pedestal section 29, and said chain ends are maintained at all times stationary while the intermediate portion of said chain III is free to travel up and down with the sleeve section 99 and the seat supporting post IOI, which movement is obviously effected by the raising and lowering movement of said sleeve section 69.

It may be here noted that the sprocket chain extends both within and without the sleeve section 99 and has its ends Joined by relatively adjustable couplings which are arranged to be conveniently adjusted from without the sleeve section 99 and the frame pedestal section 29 without dismantling any of the seat supporting members. As shown in Fig. 4, the pedestal frame section 29 is provided in its upright wall I35 with the aperture I36 through which relative adjustment of the chain terminal couplings I32 and I33 may be conveniently made, and which aperture is extended downwardly in the form of a relatively narrow slot I 31.

The chain coupling I32 at the depending terminal region of the chain II'I -s provided with aperture I36 and serves to steady said coupling when it is tightly clamped to the wall I35 of the pedestal frame section 29 by the tap bolt I40. The chain coupling I33 at the upturned terminal region of the cha n III is adapted to adjustably slide up and down upon the inner surface of the upright wall I35 of the pedestal frame section 29 to take up any excess slack or to relieve tension in said chain In, as may be desired, and said chain coupling I33 is arranged to be secured in such adjusted position by the tap bolt I, the threaded shank of which extends through said slot I31 in threaded engagement with said coupling I33, as shown in Fig. 4.

Referring further to Fig. 4 of the drawings, the chain couplings I32 and I33 are provided with the oppos'tely threaded bores I42 and I43 respectively in which the oppositely directed threaded shanks I45 and I49 of the chain adlusting screw are threadedly engaged. Said screw also includes the medial polygonal region, I41, preferably hexagonal, with its oppomtely directed shanks provided w'th right and left hand threads respectively so. that when rotated it tends to draw together or separate the couplings I32 and I33 and thereby to take up slack in the chain II 1 or to relieve tension therein, asgmay be desired.

Upward movement of the chair seat elevating elements is eifected by fluid pressure and is most satisfactorily accompl shed by applying lifting power to the pedestal sleeve section 99} to which is attached the vertically disposed cylinder I50" which has its head III rigidly enga edby t e m'e'nt proiection' I33 serving ass boss and formed unitary with said sleeve section 69, as shown in Figs. 3 and 5.

Said cylinder I50 is also engaged intermediate of its length with said sleeve section 69by the metallic strap I55 which embraces said cylinder and has its outwardly directed end regions I56 engaged by screws I51 with a suitably provided projection I59 formed on said sleeve section 69. The head I5I of the cylinder I50 is conveniently provided with the vent I80 which is arranged to be controlled by the valve comprising the screw plug I6I having the slotted head I62 by which it may berotated to open or close said vent I60 which is designed to be normally closed.

The cylinder I50 is raised andlowered by co operation with the piston I65 comprising the central separating disk I66, the packing cups I61 and I69 and the follower plates I10 and I", all being held together against the shoulder I12 on the tubular piston rod I13 by the keeper nut I15. Said piston I65 is mounted stationary with the chair frame carriage 5 and frame pedestal section 29 while the cylinder I50 is arranged to be raised and lowered together with the chair seat supporting structure comprising the sleeve section 69 and seat supporting shaft IOI.

As shown in Figs. 5, 6 and '7, the tubular piston rod I13 is carried by the piston rod supporting valve body structure I16 with which it is threadedly engaged in the boss I11 thereon provided. Said piston rod I13 provides a conduit I19 for conveyance of fluid under pressure to the cylinder I50 and connects through the pocket I80 with the fluid passageway I8I extending through the fluid release valve body structure I16 and closed at its outer end by the screw plug I82.

As best illustrated in Fig. '1, the passageway IBI in the valve body I16 is intercepted by the cylindrical chambers I85 and I86, and said valve body structure I16 is suspended in the fluid res= ervoir 1 from the superposed pedestal frame section 29 by the tap bolt I81 extending through the flange 30 of said pedestal frame section 29, and into the threaded bore I89 disposed in upturned hanger I90, and by the tap bolt I9I extending through said flange 30 into the threaded bore I92 in the upturned hanger I93.

The chamber I85 is provided with the screwthreaded tubular plug I95 threadedly engaged with the internally threaded upper enlarged region I96 of said chamber and having the upwardly projecting threaded boss I91 with which the short tubular nipple I98 is engaged by the annular; collar I99 having the inturned flange 200 engaging the laterally extending flange I with the yielding washer 202 interposed between it and the boss I91 to provide a fluid-tight joint for the conduit 203 provided by the tubular plug I95 and nipple I98, as best illustrated in Fig. 7.

Said nipple I98 connects the tubular plug I95 with the hollow spheroidal coupling 205 with which it is threadedly connected and which conples the said nipple with the, inner threadedly engaged terminal 206 of the flexible tubular fluid conductor 201 through the outer terminal 209, which is engaged with the hollow cylindrical connection fitting 2I0, see Figs. 3 and 8, which, in

turn, is connected by the union coupling 2| I with the check valve housing 2I2.

As best illustrated in Fig. 8, the check valve housing. H2 is directly connected through its passageway 2I3 with the outlet orifice 2 of the fluid pump 2l6 upon which it is mounted, with the interposed gasket 2I8, by the screws 2".-

Also, as shown in said Fig. 8, the check valve housing 2I2 includes in its passageway 2I3 the valve chamber 2 I9 in which the hollow valve plu 220 is threadedly engaged and provided with the reciprocatory plunger typevalve stem 22I which is pressed forwardly by the spring 222 so as to yieldingly engage its conical forward end region 223 with the inserted valve seat 224. Obviously, said check valve stem 22I may be forced from its seat by fluid under pressure from the fluid pump 2I5 when operated, but is adapted to prevent the return of fluid to the pump 2I5 when said pump is idle.

Referring again toFig. 8 of the drawings, the check valve housing 2I2 is extended to provide a base 225 having the annular internally threaded upturned boss 226 with which the air dome 221 is threadedly engaged in fluid-tight relation, said air dome 221 being provided with the relief vent 229 conveniently controlled by the closure screw 230 by which'the volume of air in the dome may be varied-or the air chamber 23I may be relieved, said air chamber being connected by the fluid conveying passageway 232 with the fluid passageway 2I3 through the valve chamber H9 and the intercepting check valve including the plunger stem 22I and seat 224.

Referring to Fig. 8, the inlet orifice of the fluid pump 2I5 is connected by the passageway 233 in the pump inlet fitting 235 through the depending pipe or tube 236 with the fluid strainer 231 which is suspended thereby and which depends into the sump 9 in the floor 8 of the fluid reservoir 1. Said pipe or tube 236, as bestillustrated in Fig.- 8. is connected at its upper end in screw-threaded re lation with said inlet fitting 235 and is provided at its lower end with serrations 239 and preferably terminates in abutted relation to the perforated floor 240 of the strainer 231. Said strainer may preferably be provided, as shown in Fig. 8, with the annular imperforate top plate 28! having the inner depending flange 282 rigidly secured to the pipe or tube 236, and the peripheral depending flange 283 secured in rigid relation to the respective inner and outer relatively spaced perforated concentric cylindrical walls 245 and 286 which are attached at their bottom edges respectively to the strainer floor 280 by the angled annulus 281.

The fluid pump 2 I5, which is of a known commercial type and therefore is not herein described in detail, is particularly adapted to pumping fluid such as oil for compression purposes, and is mounted on forwardly projecting bearing section 249 of the housing of the electric motor 250, with its axis of operative rotation disposed coincident with the axis of rotation of the motor armature so that the motor armature and the pump mechanism may be mounted as a unit and contemporaneously rotated. I

As shown in Figs. 3 and 8, the electric motor 250 is so supported as to minimize the consequent vibrations produced incident to the rotation of the motor armature and pressure producing elements of the pump 2I5. To best accomplish this purpose, the motor is floatingly supported in the motor supporting frame 25I, which is substantially annular in form and which is provided with the feet 252 and 253, see Figs. 3, 21 and 22, which 22, is generally annular in form and-embraces the forward region of the enlarged body portion of the electric motor 288 and is provided with cradles 259,.260,.26I and 262, relatively spaced circumferentially and having slot 263, 264, 265

are preferably composed of rubber or other nonresonant material and having embedded therein and projecting therefrom screw-threaded shanks 2", 212, 213 and 214, which may have their projecting ends threadedly engaged with the casing motor 250, and also having embedded therein shanks 215, 216, 211 and 218 projecting outwardly through the slots 263, 264, 265 and 266 in the respective cradles 259, 268, 26I and 262, and rigidly secured to their respective cradles by the nuts 219, 288, 28I and 282. As shown in Fig. 21, the threaded shanks 21I, 212, 213 and 214 are in axial alinement with the threaded shanks 215, 216, 211 and 218 but have their approaching opposed ends relatively spaced to prevent vibrations being transmitted therethrough.

Thus it will be obvious from the above description that the power unit including the electric motor 258 and its associated D p 2I5 are so mounted as to be substantially rigid with the chair seat supporting structure, while the vibrations attendant their actuation will be so completely absorbed by the supporting resilient builers 261, 268, 269 and 210 as to not be annoying to the occupant of the chair seat.

As the check valve comprising the valve plug 228 and valve plunger 22I must be backed oil to release any fluid trapped in the air dome 221, a drip pan or receptacle 285 is provided and disposed in subjacent relation to the outer end of the valve chamber 2I9, said drip pan being supported by its depending leg 286 which is engaged by the screws 281 with the outwardly extending bearing block 21 which is formed in unitary relation with the chair frame supporting carriage and which projects laterally from the wall of the fluid reservoir.

Said drip pan is provided with the discharge opening 298, see Fig. 3, having the lip 29I extending over said fluid reservoir 1, see Fig. 8, so that any discharge of fluid from the check valve chamber 2I9 will be caught by the drip pan 285 and directed back into the reservoir 1, as shown in Figs. 3 and 8.

It will be obvious from the foregoing description that the actuation of the pump 2I5 effect the drawing of fluid from the reservoir 1 through the pipe 236 into said pump, from where it is forced thereby under pressure through the passageway 2I3, check valve chamber 2I9, hollow fitting 2I0, flexible conductor 281, passageway I8I, conduit I19 which directs said fluid into the cylinder I50 causing it by cooperation with the piston I65 to rise to the position shown in Figs. 4 and 5 wherein the pedestal sleeve section 69 and seat supporting shaft IOI carrying the seat supporting cross-head I85, have been raised substantially to their maximum elevated position illustrated in Figs. 1, 4 and 5.

When the seat raising parts including the padestal sleeve section 69 and seat supporting shaft I8I and seat carrying cross-head I85 have been thus elevated to the limit of their upward move- -ment, the elevating mechanism including the motor 250 and pump 2I5 are automatically rendered inoperative by actuation of tripping mechanism adapted to break or open the electric circuit leading to said motor 250.

The tripping mechanismincludes the trip lever 295 in the form of a bell-.crank-lever, which has its inwardly projecting arm 296 extending through theaperture 291 in the side wall of the pedestal frame section 29, and disposed in the path of a stop lug 299 formed on the pedestal sleeve section 69 and arranged to be engaged thereby when said pedestal sleeve section is raised to the upper limit of its movement, as best shown in Fig. 4.

As shown in Figs. 4, 9 and 10, the trip lever 295, which is in the form of a bell-crank-lever is mounted to rock on the horizontally disposed shaft 308 which is carried by the relatively spaced bearing ears 38I and 382 projecting outwardly y from the side wall of the pedestal frame section 29 upon opposite sides of the aperture 291. The depending arm 303 of the trip lever 295 has the outwardly and laterally projecting shelf 305 terminating in the downwardly extending flap 386. At the angle of the shelf 385 and flap 386, said trip lever 295 is provided with a horizontally extending bore 301 for the pintle 389 for the depending adjustable extension 3I0 whose relatively spaced ears 3 and 3I2 straddle the trip lever 295 and rock on the pintle 309, see Figs. 9 and 10 particularly.

Again referring to Figs. 9 and 10, the depending adjustable extension 3I8 is adjustably engaged with the flap 386 of the trip lever 295 by the .set screws 3I5 and 3I6, the former being screw-threadedly engaged with said flap while the latter has its forward end engaged with the outer surface of said flap, as best shown in Fig. 18.

Said adjustable extension 3I8 terminates at its lower end region in a vertically disposed flat web 3" whose opposite sides are faced with thin plates 3I9 and 320 preferably formed of wear resisting material secured thereto by rivets 32I and 322.

As best shown in Figs. 9 and 10, the trip lever 295, through the depending adjustable extension 3I8, is arranged to effect automatic actuation of the switch controlling mechanism which determines the position of the mercury switch 325 comprising the mercury containing tube 326 being of well known construction and including terminals 329 and 330 for connection of the electric conductor wires 33l and 332, see Figs. 9 and 19.

The switch controlling mechanism, which will be hereinafter described in detail, is mounted as a unit in the switch controlling mounting bracket 333 whose base 335 is secured by screws 336 and 331 to the flange l8 of the chair frame supporting carriage 5 and whose horizontally disposed bearing shelf 339 is relatively spaced from said base 335 by the standard 338 and is provided with the vertically disposed upwardly extending panel 348, see particularly Figs. 9, 10, 11 and 12.

The mercury containing tube 326 of the switch 325 is carried by the cradle 34I which is swingingly supported at its upper end on the headed pintle 342 projecting outwardly from the upwardly extending panel 348 and which is normally held by the spiral spring 345 in the position shown in Fig. 9 to so incline the mercury containing tube 326 as to maintain the electric circuit between the source of energy and the motor 233 normally open. Said mercury containing tube 323 is removably held on its cradle 331 by the spring clip 333 which is engaged with the cradle 331 by the bolt 331, and which has its forwardly projecting snap flngers 339 and 333 embracing said mercury tube which is Prevented from endwise displacement on said cradle by the retainer 331 having the out-turned abutments 352 and 333 and being engaged with the cradle 331 by the belt 331.

The alternate or operative position of the cradle 331 and the mercury containing tube 323, in which the electric circuit between the source of energy and the motor 233 is closed, is illustrated in Fig. 19 wherein said cradle 331 and the mercury containing tube 323 have been rocked toward the left to their operative position to effect closing of said electric circuit.

The switch controlling bracket 333 comprising the base 333, standard 333, horizontally disposed shelf 333 and panel 333, includes the vertical shaft 333 mounted in suitably provided apertures in the base 335 and shelf 333 and secured in the latter by the set screw 331. Said shaft serves as an axis about which the several members of the switch controlling mechanism oscillate.

The foot actuated switch controlling pedal 362, shown in neutral-position in Figs. 3, 9, 10. 12 and 13, is mounted for oscillatory movement on the shaft 333 and has the upwardly projecting stud 333 which is connected by the link 333 with a similar stud 333 on the relatively spaced auxiliary foot actuated pedal 331 which is disposed at the opposite side of the longitudinal axial plane of the chair for convenience of the operator, and mounted for oscillatory movement on the shaft 339, projecting upwardly from the flange 13 of the frame supporting carria e 3.

Said foot actuated switch controlling pedal 332 has the laterally projecting arm 313 terminating in an upwardly extending flnger 311 which cooperates to yieldingly maintain said pedal 332 normally in its neutral position, with the opposed jaws 312 and 313 whose free ends bear against the opposite sides of said flnger 311 and also normally bear against the opposite sides of the stop lug 315 which projects forwardly from the standard 333. As best illustrated in Fig. 13, said jaws 312 and 313 are pivoted on the shaft 333 for independent movement and are connected by the spiral spring 313 which tends to yieldingly draw said jaws together.

Said laws 312 and 313 are respectively provided at their free ends with butter blocks 313 and 333 of a semi-resilient substance preferably riveted thereto as shown and extended slightly beyond the respective free ends, so arranged as to deaden the noises incident to their contact with the stop lug 313 and the finger 311.

As best shown in Fig. 12, the switch controlling mechanism includes the centrally pivoted switch actuating levers 331 and 332 mounted to independently oscillate on the shaft 333, and respectively having the relatively opposed forwardly extended beaks 333 and 333, and the rearwardly extending tails terminating in opposed preferably globular sliding contacts 393 and 333 which are arranged to bear against the opposite facing plates 313 and 323 of the depending flat web 311 of the depending adjustable extension 313.

Said switch actuating levers 381 and 332 are pivoted for independent movement and are con nected by the spiral spring 311 which tends to yieldingly draw said levers together, and to cause their respective beaks 333 and 333 to engage the respectively opposite sides of the upwardly extended finger 311, and also to cause their respective globular tail contacts 333 and 333 to yieldingly engage the respective facing plates 313 and 323 of the depending web 311 of the depending adjustable extension 313 With further reference to Fig. 12, the switch actuating lever 331 is provided with a lateral extension 331 which inclines upwardly and terminates in a relatively parallel plane slightly above the plane of the lever 331 proper, and said extension 331 carries the upwardly extending stud 339 which is arranged to engage the lug 333 depending from the switch cradle 331 into the path of said stud whereby the anti-clockwise movement of said lever 331 will cause said stud 333 by its engagement with said lug 333 to rock the cradle 331 and mercury containing tube 323 from its inoperative position shown in Fig. 9 to its operative position shown in Fig. 19, wherein the motor 253 and pump 213 are actuated to effect raising of the chair seat. This operative position of the mercury containing tube 323 is effected by movement of the foot pedal 332 to the right as indicated by the arrow and movement of its associated switch control mechanism to their relative positions illustrated in Fig. 14.

When the chair seat is maintained in its raised position by the compressed fluid in the cylinder 153, such premure may be released and the chair seat lowered by shifting the foot controlled pedal 332 toward the left from its central neutral position shown in Figs. 12 and 13 to its fluid pressure releasing position illustrated in Fig. 15 where the associated parts are so correlated that the lever 382 by its engagement with the web 311 of the depending adjustable extension 313 forces it inwardly, thus rocking the composite rocker arm comprising the trip lever 295, its depending arm 333 and depending adjustable extension 313 on the shaft 333.

As best shown in Figs. 9 and 10, the trip lever 29.: is provided with the laterally extended arm 393, having the inwardly projecting flnger 391 provided with a depressed pocket 332, in its upper surface, into which pocket 332 the downwardly directed end of the set screw 333, which is adjustably engaged in the bossed head 395 of the depending link 393, projects and is so seated as to support said link suspended for minute vertical adjustment.

As illustrated in Fig. 10, the lower end region of the link 393 depends into the reservoir 1 and has the horizontally extended foot 391 which extends beneath the valve body structure 116, see Figs. '1 and 10. Said foot 391, as shown particularly in Fig. 7, is provided with the through bore 393 having the annular seat 399 on which the thrust bearing-ball 333 rests.

As best shown in Fig. 7, said thrust bearingball 333 is normally spaced with sufficient clearance from the depending stem 331 of the fluid relief valve 332 to permit its free seating. Said valve 332 is arranged to be opened by lifting it from its seat 333 in opposition to the spiral spring 335 which encircles the upwardly extending valve stem 333 and extends between said valve 332 and the depending hollow extension 331 of the valve cap 339 into which said stem 336 extends for guidance.

Referring further to Fig. '7, the valve seat 333 is disposed in the annular somewhat resilient valve seat insert 313 in the valve housing 31 1 which is screw-threadedly engaged in the valve chamber 

